Windows 10 and RHEL 7.6 dual boot keep destroying each other (EFI)

Hello everyone,

Apologies if this appears to be something I should be able to solve by reading other posts here, I have done my best to collect as many other posts as possible but I'm not getting anywhere after a lot of work. I think I've reinstalled my operating systems at least 6-7 times each by now and need to get a firmer understanding on how to recover a dual boot without reinstalling any os.

I would like to be able to confidently do these things -

-Restore Windows 10 as a boot option if it disappears without having to reinstall windows
-Restore RHEL as a boot option if it disappears without having to reinstall it.

I've been experiencing a lot of pain since I started using RHEL 7.5-7.6 over the last week trying to get it and Windows 10 to play nice on a Z8 workstation.
they are both on their own 512 GB SSD's.
I'm surprised at this trouble because I thought EFI was supposed to solve a lot of these problems. I was hoping that my bios could take care of everything, but over time, I will experience these things -

-installing rhel will remove windows as an efi boot option (or a grub boot option). it is possible that a yum update is doing this, or the grub bootloader is when it is updated.

-getting grub2 to rebuild the bootloader will not detect windows after a rhel install and its updates to 7.6, but it seems to be able to fuction after a fresh windows install. also booting from windows media and getting it to "repair" the windows boot for windows will fail.

-sometimes, if I install windows first, and then RHEL, I will see both efi boot options in my bios! thats great, but it wont stay that way for long
That state seems to get broken by another rhel install, or possibly rebuilding with grub2, or potentially updating to 7.6 with yum (hard to say).
when I rebuild the grub config for efi, I do this-
grub2-mkconfig -o /boot/efi/EFI/redhat/grub.cfg

At some point, the windows option can just disapear from my grub bootloader. and it will also disapear from my efi options in the bios. its hard to know exactly what the cause is there.

Even when I'll take a clonezilla image of both full disks at the point after a fresh install, that working state of having both efi options to boot from sometimes cannot be restored from the full disk images and all their partitions which is baffling to me. perhaps clonezilla is to blame, I'm not sure.

here are some more details on my configuration-

I have windows installed on /dev/sda (512GB SATA SSD)
and rhel 7.6 on /dev/sdb (encrypted) (another 512GB SATA SSD)

note that if I boot the windows installer, the first drive on the list is actually another 1TB M2 turbo drive (/dev/nvme0n1) but that is not for the OS, its a spare for production later.

I have legacy mode disabled, and secure boot mode disabled in the HP bios.

Thanks if anyone can provide steps for both resting of boot options in the future, I'm sure I will experience a failure again of both soon and will be able to test either case.